Method of treating ingots.



H. 0. RYDING. A METHOD OF TREATING mews. lPPLIOATI ON FILED MAR. 31;19.13. REN-EWFD FEB. 12, 19M.

1- ,1 O8,'24;3. Patented Aug 25, 1914. I

' novel method been carried TED STATES rA'rnnT orrron.

HER-BERT G. RYDING, OF BIBMIN'IXHAM, ALABAMA.

. METHOD OF TREATING ING-O-T-S.

amazes.

Application filed March 31, 1913, Serial No. 757,987.

To all whom it may concern Be it known that I, HERBERT C. RYDING, acitizen of the United States, residing at Birmingham, in the county ofJelferson and State of Alabama, have new and useful Improvements inMethods of Treating Ingots,of which the following is a specification.

My invention relates to the art of metal rolling and-has particularreference to a of treating steelingots prior to thereduction thereof byrolling.

During the past two or three. years the subject of rail failures haspersistently forced itself upon the attention of railway managers andrail manufacturers, with the result that searching investigations haveout in connection withthe present methods of manufacture, and subsequenttreatment of rails, the object of which-was to determine if possiblewhat were the real causes leading up to rail failures.

segregating out from the mass of detail on this subject the chief causesof failure, it will be found that by far the greater number of failuresproceed from one or two causes: First in importance I believe is seamysteel and, second, piped ingots.

Seams in rails either proceed from blow holes in the ingot or from theformation of cracks in the sides, commonly noted during the passage ofthe ingot through the first few passes in the blooming mill rolls. Byfar the greater number of these seams proceed from the cracks caused bythe action of rolling on the ingot and are more dangerous than thoseseams caused by blow holes in ingots because they all penetrate throughthe skin of the rail, whereas those resulting from blow holes do not,except in some cases where they are located directly under the outerwall of the ingot.

Blow hole cavities in ingots not containing any foreign matter have beenproven by microscopic investigation to weld so perfectly that all tracesof same are usually eliminated. We can, the seam resulting from blowhole cavities from our consideration of this trouble and confineourselves which penetrates through the skin of the rail. This seam iscaused by the action of the blooming rolls on the ingot metal crackingthe sides of the ingot. The structure of the metal in the ingot, as aresult of being cast, ,is of a very coarse crystalline therefore,eliminate to the dangerous seam Specification of Letters Patent.

invented certa1n subjected to actual erable importance,

Patented Aug. 25, 1914'. Renewed February 12, 191 1. Serial No. 818,328.

nature and possessing very little ductility, ruptures when elongatedbeyond its elastic limit. The work of the blooming mill tends toelongate the ingot very m, idly and before all the four sides of theingot can be contact with the rolls and receive that amount'of-worknecessary to reduce the coarse crystalline structure and increase theductility of the metal, the sides, not having had any work, usuallyrupture. If the ductility of the metal. .in the walls of the ingot canbe increased to any considerable extent before bloomed the cause of thedangerous seam in the rail will be largely removed. To accomplish this Ipropose to subject the ingot to a primary rolling process preferably infront of t is soaking pit or heating furnaces. To accomplish this Iwould put in a small, slow speed-reversing mill in arrangement the sameas an ordinary blooming mill. The ingots, after having been stripped andallowed to reach a satisfactory temperature, would be subiected to theaction of the rolls in the mill until the ingot is squared up from topto bottom, and then charged into the soaking pit. The operation of thismill can be regulated work on the metal, and by properly designing therolls a good proportion of the work can be done without undulyelongating the ingot. This form of roll pass isxif considas it isintended not only to render the metal of the sides of the in ot moreductile, but may have considerable bearing on the pipe in the ingot,which is considered of second importance in causing rail failures.

The primary when the ingot may still contain some liquid metal or isstill in a plastic condition in the center will, if rolled with theheaviest draft in the direction from bottom to top of ingot,

serve to weld the sides of the cav ty formed in all ingots as a resultof the contraction due to solidification of the metal. After thistreatment the ingot should be practically solid from one end to theother and remain so as the temperature of the mass will not beverymaterially reduced before going to the blooming mill.

It has been found by tests that the seams proceeding from fissuresresulting from the heavy reduction inthe first few passes through theblooming mill are not welded in later rolling operations and present thoipoot, 1

so as not to put too severe rolling of the ingot at a time in thefinished product. By my method, such seams are eliminated for the reasonthat the surfaces of the ingot are made tough and dense by reason of thegentler reduction of the first rolling operation, and for the reasonthat the sides of the ingot are made parallel and the subsequentreduction in the blooming mill is not unequal at different points in thelength of the ingot. A result of the elimination of such seams is arolled product which has a much. greater ductility, and its trans versestrength is greatly mcreased. The

elimination of the seam, the transverse strength is an object sought. Itfercnt forms of mechanisms may be employed for carrying out my method. Ihave, however, shown diagrammatically in the accompanying drawing, anarrangement whereby the method may advantageously be carried out.

In the drawing the figure is a diagrammatic illustration of a rollingmill in which there are shown ingot tracks 10, served by a run-aroundtrack 11. The usual soaking pits 12 are provided.

Interposed between the ingot stripping track and the soaking pit is amill 13, which receives the ingots shortly after they are stripped andby light passes, serves to make therefore, increases of the rail, whichuniform the cross section of the ingot atthe same time densifying andimproving the outer structure thereof and inasmuch as the process isperfectly carried out while the interior of the ingot is still molten,the molten metal will be forced into any pipes which may theretoforehave formed. In this prel iminary Working the ingot is not matei iallyelongated. After leaving the mill 13 the'ingots are transferred by 14.,to the track 15,

which serves thesoaking plts.

steps may follow rolling of rails or other shapes.

It will be noted that my novel method has the effect of gently workingthe sides of the ingot whereby the surfaces thereof are made more denseand homogeneous, these tough-- ened surfaces being thereafter more ableto Copies of this patent may be obtained for is obvious that dif=' thehydraulic pusher, while' t he interior of the semi-fluid condition,After, the ingots are removed from the. "Ition' of the ingot issoaking-pits they are delivered at once to the blooming mill 16, fromwhich point the the usual course in the five cents each, by addressingthe Washllnmomlll. Q.

withstand the heavy reduction in'the first pass of the blooming mill.Simultaneously the molten metal contained in the interior of the ingot,is pressed into and thereby caused to eliminate any pipes theretoforeformed thus making the entire body of the ingot of sists in subjectingthem after stripping from the molds and prior to treatment in a soakingpit, to a rolling action, then reheating the ingots and finally rollingthe same into a finished shape, substantiallyas described.

. 2. A method of treating ingotswhich con-' 'sists in subjecting themafter stripping fromthe molds and .prior to reheating in a soaking pit,to a rolling operation'whereby the ingot is-reduced in cross section andthe surfaces thereof rendered more tough, then rebeating the ingot andfinally rolling same into a finished shape, substantially as described.3

3. A method of treating ingots which consists in stripping the same fromthe molds, then slightly red area of the ingots by light passes througha rolling mill, whereby the cross section of the ingot is made uniformand the surfaces made more tough and less crystalline, then reheatingthe ingot,and finally rolling the same into a finished shape,substantially as described.

4. The method of treating ingots, which consists in stripping the samefrom the mold, then slightly reducing the cross sectional area .pftheingot in the rolls of a rolling mill whereby the cross secmade uniform,its surfaces are made tough and less crystalline, then reheating theingot, and finally rolling the same into the desired form, substantiallyas described. l HERBERT G. RYDING.

Witnesses:

P. V. KoLB, Class. F. MURRAY.

eommissloner of Iatents,

ucing the cross sectionalingot is still in a" the

